• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.330-334
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• 2004

A new SEPIC-Flyback converter is proposed. The proposed converter is the integration of SEPIC and Flyback converter. Not only SEPIC output but also Flyback output could be fully regulated by constant frequency PWM control. Merged SEPIC and Flyback topology can share the transformer and power MOSFET. When the switch turns on, one topology operates via capacitive energy transfer. The other topology acts as inductive energy transfer while the switch is off. So, it can increase power density per one cycle. The experimental result is presented and verified.

• YAKHAK HOEJI
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• v.52 no.1
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• pp.43-47
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• 2008

To determine the regulatory roles of PDE4 inhibitor on LPS-induced osteoclastogenesis, we investigated the effect of a PDE4 inhibitor on osteoclast formation in the presence of LPS. A specific PDE4 inhibitor, rolipram, increased LPS-induced osteoclast formation in cocultures. To verify that whether rolipram acts indirectly on osteoblasts, we investigated the TRANCE and COX-2 mRNA expression levels in osteoblasts. Treatment of rolipram increased the expression of TRANCE and COX-2 mRNA in osteoblasts stimulated by LPS. On the contrary, rolipram did not augment the number of osteoclasts differentiated from bone marrow cells by LPS. In conclusion, the stimulation of LPS-induced osteoclast formation by the PDE4 inhibitor are attributable to its indirect effect on osteoblasts, not to their direct effect on bone marrow-derived osteoclast precursors.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2571-2574
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• 2010

We investigate the mechanism of $S_NAr$ fluorination reactions under the influence of protic solvents and ions. We find that counterion or protic solvent alone retards the $S_NAr$ reactions, but together they may promote the reaction. In this mechanism, the protic solvent acts on the counterion as a Lewis base, and the nucleophile reacts as an ion pair. We also show that an anion (mesylate) may exhibit catalytic effects, suggesting the role of ionic liquids for accelerating the $S_NAr$ reactions.

• BMB Reports
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• v.47 no.7
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• pp.369-375
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• 2014

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic bioactive peptide that was first isolated from an ovine hypothalamus in 1989. PACAP belongs to the secretin/glucagon/vasoactive intestinal polypeptide (VIP) superfamily. PACAP is widely distributed in the central and peripheral nervous systems and acts as a neurotransmitter, neuromodulator, and neurotrophic factor via three major receptors (PAC1, VPAC1, and VPAC2). Recent studies have shown a neuroprotective role of PACAP using in vitro and in vivo models. In this review, we briefly summarize the current findings on the neurotrophic and neuroprotective effects of PACAP in different brain injury models, such as cerebral ischemia, Parkinson's disease (PD), and Alzheimer's disease (AD). This review will provide information for the future development of therapeutic strategies in treatment of these neurodegenerative diseases.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.165-168
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• 2004

Carbon nanotube is a geometrical frame-like structure and the primary bonds between two nearest-neighboring atoms act like beam members, whereas an individual atom acts as the joint of the related beam members. The sectional property parameters of these beam members are obtained from molecular mechanics. Computations of the elastic deformation of single-walled carbon nanotubes reveal that the Young's moduli of carbon nanotubes vary with the tube diameter and are affected by their helicity. With increasing tube diameter, the Young's moduli of carbon nanotubes approach the Young's modulus of graphite.

• Kyungpook Mathematical Journal
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• v.57 no.3
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• pp.371-383
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• 2017

Let M be a matroid. We study the expansions of M mainly to see how the combinatorial properties of M and its expansions are related to each other. It is shown that M is a graphic, binary or a transversal matroid if and only if an arbitrary expansion of M has the same property. Then we introduce a new functor, called contraction, which acts in contrast to expansion functor. As a main result of paper, we prove that a matroid M satisfies White's conjecture if and only if an arbitrary expansion of M does. It follows that it suffices to focus on the contraction of a given matroid for checking whether the matroid satisfies White's conjecture. Finally, some classes of matroids satisfying White's conjecture are presented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.617-620
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• 1999

To reduce the consumption of chemicals and ultra pure water(UPW) in cleaning process used in device manufacturing, we proposed wet processes that use electrolytic ionized water(EIW), which is generated by electrolysis of a diluted electrolyte solution or UPW and systemically investicate the EIW\`s characteristics. EIW\`s pH values are increased in cathode chamber and decreased in anode chamber according to the electrolysis time and its varied ratio is reduced with time increasement. The variation of pH and ORP is increased accordin to the applied voltage until critical voltage. But more than that voltage, the variation is decreased because of ion\`s scattering effect. When electrolyte is added, the effects of electrolysis is increased because electrolyte acts as catalyst. But when the density of electrolyte is increased more than critical value, ion\`s flowage is obstructed and the effects of electrolysis is decreased.

• East Asian Economic Review
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• v.23 no.3
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• pp.311-329
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• 2019

Since China's opening to international trade, the rapid growth of the country's export sector has been coupled by an intensification of migratory outflows of ethnic Chinese. The literature has already stressed the beneficial role of migration in enhancing bilateral trade. The present paper applies a gravity model in order to capture the impact of migration on Chinese exports for a relatively long period of time (1995-2017) where significant developments take place. We estimated four regressions, each of them confirming the positive network effects of migration for boosting export growth. Apart from the main finding, it appears that the role of institutional and geographical proximity can prove to be complementary for trade enhancement. The results finally suggest mixed effects due to the countries' import openness, indicating that China's free trade agreements acts as a substitute for smoothing trade competition from third countries.

• Journal of architectural history
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• v.30 no.6
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• pp.23-32
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• 2021

This study was described with a focus on the maintenance and management of Local Confucian School(Hyanggyo) architecture, centering around cases investigated through official documents written in the 1910s. In 1910, by the Japanese imperial rule, the regulations on Local Confucian School(Hyanggyo) property were enacted, and the income was paid solely to elementary school education expenses and ancestral rites. Through this process, many Local Confucian School(Hyanggyo) buildings were destroyed while only the space for ritual sacrifices remained by the Japanese colonial rule. In particular, as the land, which was the basis of Local Confucian School's property, was sold for various reasons, the finances gradually deteriorated. In addition, as the architectural acts that Local Confucian School preserves itself are restricted, it loses its original character. This study was of great significance that identified the intention to dispose of Local Confucian School(Hyanggyo) property by Japanese imperialism in the 1910s and clarified the purpose of its disposal.

• Asia Marketing Journal
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• v.25 no.4
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• pp.194-206
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• 2024

The study aimed to analyze jay-customer behavior's impact on service industry employees' job stress to understand the importance of personnel management. Additionally, it aimed to identify strategies for managing job stress by examining perceived organizational support's moderating effects. The results show that the subdimensions of jay-customer behavior (i.e., verbal aggression, physical aggression, and sexual harassment) positively influenced employees' job stress. Second, job stress acts as a mediator between customer verbal and physical aggression and customer orientation, but not between customer sexual harassment and customer orientation. Third, organizational support had a moderating effect on the association between customer verbal aggression and job stress. This study demonstrates how jay-customer behavior negatively affects employees and threatens their well-being. It not only enriches the research on jay-customer behavior but also provides implications for service companies toward developing internal marketing strategies for enhancing employee happiness and fostering customer orientation.